To be honest I didn't read that article - too long. But in real world, having used 99designs several times and finding some designers we use regularly that we discovered there - it works well.
With all due respect, you're evaluating these designers as someone without a good deal of design knowledge (my assumption). The designers you like are creating things for you that apply to your personal taste but may not be "good design", instill trust in your company, increase conversions etc.
All my company does is optimize for conversions and that is what my last company that had 100 people did... I know exactly what works for conversions and split test tons of options. 99designs is fine and people who refuse to acknowledge that fact are doing themselves a disservice.
lol - you downvoted all my posts b/c you're mad - nice.